Thanks man I really appreciate itI have a couple. I'm a medium in 99.5% of RRL and mine our mediums. They're definitely slim fitting, especially after being washed. But they stretch out even after wearing a couple hours. Super soft and comfortable. And a really great weight. Not thin but not super thick, if that makes sense. And mine have held up great. I'd definitely recommend, especially when they hit 40% off.
@kcinirni: I'd guess you're a small. If you want it as a layer under a shirt, I'd start with a small. That's how I wear mine. If you're just going to wear the henley and don't like the look of a really close fit, try a medium. But the sleeves might be a tad long.